This systematic review and comparative meta-analysis aims to evaluate the effects of matcha tea (green tea) consumption on cognitive function, assessing both immediate cognitive improvements and long-term cognitive benefits. 

Green tea has demonstrated potential for impacting cognitive dysfunction, as evidenced by experimental studies. However, its effects on humans, especially at typical daily consumption levels, remain uncertain. Understanding the relationship between matcha tea and cognitive function is essential for promoting effective nutritional interventions that can enhance cognitive health across diverse populations.

Following the PRISMA guidelines, a systematic search was conducted in the databases PubMed, EMBASE, Cochrane, Web of Science, and Scopus, focusing exclusively on English-language articles.  A random-effects model was used to calculate the Proportions, with 95% confidence intervals (CIs) and a significance level of 5%. Statistical analyses were performed using RStudio version 4.2.3.

From 302 studies initially found, 12 studies with 569 patients were included in the analysis. Of these patients, 207 were male and 360 were female, with a mean age of 53.76 years (± 20.64). The difference in cognitive function, measured by the Mini-Mental State Examination (MMSE),Showed a non-significant statistical improvement in the placebo group compared to the experimental group (MD=-0.42, 95% CI: -0.56 to -0.27; p=0.54; I²=0%). No substantial heterogeneity was observed between the studies (I²=0%). Furthermore,  the studies regarding the use of matcha for short-term cognitive improvement do not present a statistically significant difference.

The overall analysis found no statistically significant differences associated with matcha consumption regarding cognitive improvements. The variability in other cognitive tests complicates the analysis and limits the ability to draw definitive conclusions. Therefore, further research with standardized methodologies is needed to clarify matcha's effects on cognitive function.